4.asm

几个接口实验的代码。内含：8253、8255、8237、8251、DA0832、AD0809等芯片的实验代码！

								
DATA SEGMENT
TABLE DW 0101H,0102H,0104H,0108H,0110H,0120H,0140H,0180H
      DW 0201H,0202H,0204H,0208H,0210H,0220H,0240H,0280H
      DW 0401H,0402H,0404H,0408H,0410H,0420H,0440H,0480H
CHAR  DB'CDEFBA9845673210WXYSFPMG'
MESS  DB'Press a key on the small keyboard!',0AH,0DH
      DB'It will display on the screen!',0AH,0DH
      DB'Press R key,return to DOS!',0AH,0DH,'$'


DATA ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA
START: MOV AX,DATA
       MOV DS,AX
       MOV DX,OFFSET MESS
        MOV AH,09
        INT 21H
Q1:     MOV AL,82H
        MOV DX,21BH;
        OUT DX,AL
Q2:     MOV AL,00
        MOV DX,218H
        OUT DX,AL
        MOV DX,219H
        IN  AL,DX	
        AND AL,0FFH	
        CMP AL,0FFH
	JZ Q2
	MOV BL,AL
MOV CX,2
BB:CALL DELAY
LOOP BB
	MOV DX,21BH
	MOV AL,90H
        OUT DX,AL
	MOV DX,219H
	MOV AL,BL
	OUT DX,AL
	MOV DX,218H
	IN AL,DX
	AND AL,0FFH
 	MOV AH,BL
	NOT AX
	MOV SI,OFFSET TABLE
        MOV DI,OFFSET CHAR
	MOV CX,24
Q4:	CMP AX,[SI]
	JZ Q5
	ADD SI,02
	INC DI
	LOOP Q4
	JMP Q1
Q5: 	MOV DL,[DI]
	CMP DL,'0'
	JZ Q6
	MOV AH,02H
	INT 21H
	JMP Q1
Q6:     MOV AX,4C00H
	INT 21H
DELAY  PROC
       PUSH CX
	MOV AH,86H
	MOV CX,0
	MOV DX,20000
	INT 15H
	POP CX
	RET
DELAY  ENDP
CODE    ENDS
END     START

;线路:
;8255.CS ------------ 218-21F